The authentication mechanism selected by your application to access the API. Basic is the Base64 encoding of the IBM Connections Cloud username and password: Base64(username:password). For example, Base64(twatson@us.ibm.com:password).Bearer is the oauth 2.0 access token that is generated when the user grants your application access to IBM Connections Cloud services. See the reference topic "OAuth 2.0 APIs for web server flow" for more information.